This study aims to investigate if protein supplementation increases the benefits of exercise training in the elderly with sarcopenic obesity undergoing caloric restriction.
Protocol amendment and primary outcomes: In August 2021, during participant recruitment and before treatment-group unblinding, database lock, and any unblinded between-group analyses, an amendment to the study protocol and Statistical Analysis Plan was approved by the Institutional Review Board/Ethics Committee (CAAE 04234918.1.0000.0065, version 4). The amendment specified four primary lean-mass outcomes: total fat-free mass (TFFM), appendicular fat-free mass (AFFM), appendicular fat-free mass adjusted for body mass index (AFFM/BMI), and leg fat-free mass (LFFM). The Statistical Analysis Plan also prespecified the use of Hochberg's procedure to control the family-wise type I error rate across these four co-primary outcomes. The structured Primary Outcome Measures section of the ClinicalTrials.gov record was subsequently updated on May 28, 2025. This update reflects the outcome framework specified in the August 2021 protocol amendment and Statistical Analysis Plan.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
105
40g of whey protein in the breakfast;
42g of isocaloric supplement in the breakfast;
University of Sao Paulo
São Paulo, São Paulo, Brazil
Percentage of Fat-free Mass
Fat-free mass evaluated through dual-energy x-ray absorptiometry (DEXA) and reported as percentage
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Appendicular Fat-free Mass
Appendicular fat-free mass was evaluated through dual-energy x-ray absorptiometry (DEXA) and calculated as the sum of the fat-free mass of the upper and lower limbs.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Appendicular Fat-free Mass to Body Mass Index Ratio
The appendicular fat-free mass (AFFM) was assessed using dual-energy X-ray absorptiometry (DXA) and expressed in kilograms (kg). The body mass index (BMI) was calculated as weight in kilograms divided by the square of height in meters (kg/m²). The AFFM/BMI ratio was computed by dividing AFFM (kg) by BMI (kg/m²), resulting in a unitless ratio. Higher values indicate greater muscle mass relative to body size
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Leg Fat-free Mass
Appendicular fat-free mass was evaluated through dual-energy x-ray absorptiometry (DEXA) and calculated as the sum of the fat-free mass of the lower limbs.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Fat-mass
Fat mass was evaluated trough dual-energy x-ray absorptiometry (DEXA) and reported as percentage.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Quadriceps Cross-sectional Area (CSA)
Quadriceps cross-sectional area (CSA) was assessed by computed tomography imaging
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Rectus Femoris Cross-sectional Area (CSA)
Rectus femoris cross-sectional area (CSA) was assessed by B-mode ultrasound.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Vastus Lateralis Cross-sectional Area (CSA)
Vastus lateralis cross-sectional area (CSA) was assessed by B-mode ultrasound.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Muscle Fiber Cross-sectional Area (fCSA)- Type I
Muscle fiber cross-sectional area (type I) was assessed using an immunostaining assay of muscle tissue samples obtained through percutaneous muscle biopsy
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Muscle Fiber Cross-sectional Area (fCSA)- Type II
Muscle fiber cross-sectional area (type II) was assessed using an immunostaining assay of muscle tissue samples obtained through percutaneous muscle biopsy
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Serum Levels of C-terminal Telopeptide of Type I Collagen (CTX-I)
Bone turnover was assessed by an automated electrochemiluminescence method.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Serum Levels of Procollagen Type I N-terminal Propeptide - (P1NP)
Bone turnover was assessed by an automated electrochemiluminescence method.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Mineral Density (Whole-body)
bone mineral density (whole-body) evaluated trough dual-energy x-ray absorptiometry (DEXA)
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Mineral Density (Femur Neck)
bone mineral density (femur neck) evaluated trough dual-energy x-ray absorptiometry (DEXA)
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Mineral Density (Total Hip)
bone mineral density (total hip) evaluated trough dual-energy x-ray absorptiometry (DEXA)
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Mineral Density (Lumbar Spine)
bone mineral density (lumbar spine) evaluated trough dual-energy x-ray absorptiometry (DEXA)
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Microarchitecture (Total Volumetric Density)
Bone microarchitecture (total volumetric density) was assessed at the distal region of the radius of the non-dominant limb using a high-resolution peripheral quantitative computed tomography (HR-pQCT)
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Microarchitecture (Trabecular Volumetric Density)
Bone microarchitecture (trabecular volumetric density) was assessed at the distal region of the radius of the non-dominant limb using a high-resolution peripheral quantitative computed tomography (HR-pQCT)
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Microarchitecture (Cortical Volumetric Density)
Bone microarchitecture (cortical volumetric density) was assessed at the distal region of the radius of the non-dominant limb using a high-resolution peripheral quantitative computed tomography (HR-pQCT)
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Microarchitecture (BV/TV)
Bone microarchitecture (BV/TV) was assessed at the distal region of the radius of the non-dominant limb using high-resolution peripheral quantitative computed tomography (HR-pQCT). Specifically, trabecular bone volume fraction (BV/TV) is computed as the ratio of the trabecular bone mineral density (Tb.vBMD in mg HA/cm3) and 1200 mg HA/cm3, which is assumed to be the density of fully mineralized bone. Afterwards, the values were multiplied by 100 to reflect the percentage of trabecular bone volume fraction.
Time frame: 16 weeks
Bone Microarchitecture (Trabecular Number - Tb. N)
The trabecular number (Tb.N) was analyzed using the ridge extraction technique in high-resolution peripheral quantitative computed tomography (HR-pQCT). In this approach, the trabeculae were treated as elongated structures resembling ridges. The technique involves detecting the central axis (ridge) of each trabecular element in a 3D image.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Microarchitecture (Trabecular Separation)
Trabecular separation (Tb.Sp), represents the average distance between trabeculae in the trabecular bone region. It was assessed using the distance transformation method, applied to the background (void space) of the trabecular structure. The transformation method measures the distance from each voxel (3D pixel) in the void space to the nearest trabecular element, and the average of these distances is then calculated. This method enables precise quantification of trabecular spacing in high-resolution 3D images. The separation is inversely related to trabecular density, as closer trabeculae indicate a higher bone volume fraction (BV/TV) and a denser bone network. The calculation of trabecular separation can be expressed as: Tb.Sp = 1- BV/TV : Tb.N
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Microarchitecture (Trabecular Thickness)
Trabecular thickness (Tb.Th) represents the average thickness of trabecular bone elements. It was assessed by calculating the mean thickness of the segmented trabecular structure, using the distance transformation method applied to the trabecular bone tissue. The trabecular thickness is calculated as a ratio of the bone volume fraction (BV/TV) to trabecular number (Tb.N): Tb.Th =BV/TV : Tb.N
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Microarchitecture (Cortical Porosity)
Cortical porosity (Ct.Po) is quantified using a density-based approach that segments bone into three compartments: compact cortex, transitional zone, and trabecular compartment. Voxels with a density below 1000 mg HA/cm³ indicate the presence of void space (pores), and porosity is estimated as the ratio of void space in each voxel. The mean of this ratio is calculated across all voxels in the compartment of interest, and the values were multiplied by 100. This method captures pores with diameters below the scanner's spatial resolution but relies on the assumption of fixed bone tissue mineral density and may be susceptible to image noise and beam hardening.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Microarchitecture (Cortical Thickness)
Bone microarchitecture (cortical thickness) wwas assessed at the distal region of the radius of the non-dominant limb using a high-resolution peripheral quantitative computed tomography (HR-pQCT)
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Microarchitecture (Cortical Pore Diameter)
Bone microarchitecture (cortical pore diameter) was assessed at the distal region of the radius of the non-dominant limb using a high-resolution peripheral quantitative computed tomography (HR-pQCT)
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Microarchitecture (Stiffness)
Stiffness (kN/mm) is defined as the total reaction force of the model divided by the applied displacement. It represents the resistance of a material or structure to deformation under an applied load. A higher stiffness value indicates greater resistance to deformation, while a lower value suggests more flexibility.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Bone Microarchitecture (Estimated Failure Load)
Estimated failure load is indirectly calculated from linear finite element (FE) models using a yield criterion. The failure load is estimated when a specified volume of bone tissue (critical volume) exceeds a critical strain threshold, at which point the model is assumed to have yielded. This approach is often based on the Pistoia criterion, which is used to predict the point of failure in the material based on its mechanical properties and deformation behavior.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Isometric Muscle Strength - Handgrip
Isometric muscle strength was evaluated using a handgrip dynamometer (Jamar®, Sammons Preston Rolyan, USA).
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Muscle Strength - Upper Limbs
Muscle strength was evaluated using maximal dynamic strength test \[1RM\])
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Muscle Strength - Lower Limbs
Muscle strength was evaluated using maximal dynamic strength test \[1RM\])
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Muscle Function (Short Physical Performance Battery)
Muscle function evaluated through battery of tests - Short Physical Performance Battery (SPPB). The SPPB is a standardized assessment of lower extremity function that includes three components: balance tests, gait speed over 4 meters, and the five-times sit-to-stand test. Each component is scored from 0 to 4, with a total score ranging from 0 to 12. Higher scores indicate better physical performance. The SPPB is widely used to evaluate physical function, predict disability, and monitor health status in older adults.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Muscle Function (30-s Sit-to-stand Test)
The 30-second sit-to-stand test is a simple measure of lower body strength and functional capacity. Participants are asked to rise from a seated position and sit back down as many times as possible within 30 seconds. The total number of complete sit-to-stand repetitions performed in the given time is recorded. This test is commonly used to assess physical fitness and mobility, particularly in older adults or individuals with health conditions.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Muscle Function (Timed-up-and-go)
The Timed Up and Go (TUG) test is a simple and widely used assessment of mobility and balance. Participants are asked to stand up from a seated position, walk 3 meters, turn around, walk back to the chair, and sit down again, all as quickly as possible. The total time taken to complete the task is recorded. The TUG test is commonly used to evaluate functional mobility, fall risk, and the ability to perform daily activities, particularly in older adults or individuals with mobility impairments.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Muscle Function (Gait Speed)
Muscle function evaluated through 4-m gait speed test. The 4-meter usual gait speed test measures the time it takes for a participant to walk a distance of 4 meters at their usual pace. The test is commonly used to assess walking speed, which is an important indicator of mobility, physical function, and overall health. The time taken to complete the 4-meter walk is recorded and used to evaluate the individual's functional capacity, with slower times potentially indicating mobility impairments or a higher risk of adverse health outcomes.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Cardiorespiratory Fitness
Cardiorespiratory fitness was evaluated by maximal oxygen uptake (VO²max) during a maximal exercise test on a treadmill
Time frame: 16 weeks
Insulin Sensitivity as Assessed by Surrogates of Insulin Sensitivity
Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) is a method used to estimate insulin resistance based on fasting plasma glucose and fasting insulin levels. It is calculated using the following formula: HOMA-IR = (fasting insulin \[µU/mL\] × fasting glucose \[mg/dL\]) / 405. Higher values of HOMA-IR indicate greater insulin resistance and are considered worse. There is no fixed theoretical maximum value, but typical reference ranges in healthy individuals are usually \<2. Values above this threshold may suggest impaired insulin sensitivity or metabolic dysfunction. The HOMA-IR is widely used in clinical and research settings as a surrogate marker for insulin resistance.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)
Brachial Flow-mediated Dilation (FMD)
Brachial flow-mediated dilation (FMD) is a non-invasive measure of endothelial function, assessed using high-resolution B-mode ultrasound. The test evaluates the percent change in brachial artery diameter in response to increased blood flow (reactive hyperemia) following 3 minutes of cuff occlusion, on the forearm. An increase in arterial diameter after cuff release indicates vasodilation mediated by nitric oxide. Higher FMD values reflect better endothelial function, whereas lower values are associated with cardiovascular risk and impaired vascular health.
Time frame: Baseline (Pre-intervention) and 16 weeks (Post-intervention)